Nasal applicator

ABSTRACT

Nasal applicators are an important aid for introducing powdery, pharmacologically active medicaments into the nasopharyngeal space of a patient. The present nasal applicator is based on a manually actuated compressed air source connected to an inflow channel (8) for generating a compressed air jet, a storage container (3) for the medicament and a metering device for making available a portioned-off quantity of the medicament which is caught by the compressed air jet and transported through an outflow channel (9) into the nose. The metering device consists of a metering drum (5) in which the storage container (3) for the medicament is formed by the interior of the metering drum (5). In addition, the inflow channel (8) is connected to one end of a metering channel (7) and the outflow channel (9) to the other end of the metering channel (7). The quantity of medicament made available in one portioning chamber (13) of the metering drum (5) protrudes into the metering channel (7) in such a manner that it is completely caught by the compressed air jet and transported into the nasal cavities.

The invention relates to a device for introducing a powdery medicamentinto the nose.

Powdery medicaments are used for treating inflammatory and allergicdiseases of the nasal mucosa.

In addition to this, nasal inhalation is also possible for certainactive substances which are to be administered systemically (e.g.short-chain peptides). In this way, the injections which patients findunpleasant are in many cases avoided.

Some of the appliances which have been developed for nasaladministration of powders contain the active substance in portioned-offform in hard gelatin capsules, which have to be loaded into the inhalerappliance and opened up immediately prior to inhalation.

This loading procedure is awkward and cannot be done satisfactorily byelderly people with rheumatic symptoms or poor eyesight.

To overcome this drawback, a self-metering appliance has been developed(German Offenlegungsschrift 2,529,522) in which the awkward loadingprocedure is dispensed with. A disadvantage of this appliance, however,is that the patient has to take the powder up by means of activeinhalation. It is not possible to do this satisfactorily, especiallywhen the mucous membranes are swollen.

In order to blow the active substance actively into the nose, applianceshave also been developed in which the active substance is present indissolved or suspended form in a pressure-liquefied propellent gas. Onactuating the metering valve, a portioned-off quantity of the activesubstance suspension is released. The propellant which is under inherentvapour pressure evaporates immediately, disperses the active substanceand blows into the nasal orifice. A disadvantage of this method ofadministration lies in the use of pressure-liquefied propellants whichadditionally have to be taken up by the patient's body. Furtherauxiliaries such as, for example, valve lubricants, antiflocculatingagents etc., often have to be added to the formulations. Finally, thepropellants used in the pharmaceuticals sector are also criticizedbecause of their damaging influence on the environment (e.g.contribution to warming of the earth's atmosphere and/or destruction ofthe ozone layer).

The object set was to develop a user-friendly, self-metering inhalerappliance which manages without using pressure-liquefied propellants andwhich blows the active substance actively into the nasal cavity.

This object is achieved by the invention as specified in claim 1.

The claims subsequent thereto represent further advantageous embodimentsof the device according to the invention.

As a result of such a configuration, a device of the generic type isobtained which is of a simplified structure and of improved usefulnessand safety. The mechanical outlay is greatly reduced. The quantity isbrought into the position ready for delivery at rest. The user canconcentrate on introduction of the active substance. In concrete terms,the applicator is designed, according to the invention, such that themetering arrangement consists of a metering drum in which the storagecontainer for the medicament is formed by the interior of the meteringdrum, such that the inflow channel is connected to one end of themetering channel, and the outflow channel is connected to the other endof the metering channel, and such that the quantity of medicament whichhas been made ready in a portioning aperture of the metering drumprotrudes into the metering channel. The interior of the metering drumis now used for forming the reservoir. Its content is kept in motion.This content passes by the shortest route into the standby positionready for delivery. Discharging takes place there, with no residuesremaining behind. Because of the stated orientation and sequence of thefunctional areas, no particles can fall back. The compressed air strikesin the first instance against the quantity of medicament and flows intothe exactly positioned and portioned-off, exposed heap of themedicament. The dome-shaped zone presented is rapidly carded off,swirled or dispersed, and, upon actuation of the compressed air source,is administered to the target site. The medicament is blown counter tothe effect of gravity. Incorrect holding is ruled out in practice, sincethe position of the metering drum suggests the correct handling, and theoutflow channel lying at the other, upper end, with the applicatornozzle as transfer bridge, is easily recognizable to the user. Inaddition, there is no potential risk of an overdosage forming; aquantity of powder which has not been administered disappears in thedirection of the reservoir. It is not added to in the next cycle. Asregards the design of the metering drum, this is configured in such amanner that it has a rotary sleeve equipped with portioning apertures.The portioning apertures arranged at a uniform angular distribution dipinto the powder reservoir as a remit of the mixing-drum-like rotation ofthe metering drum, without pressing etc. occurring. The metering givesthe correct volume, including the penultimate portion and, ifappropriate, right up to the final portion. Also, as a result of usingthe drum movement, the medicament does not agglomerate. It isfurthermore proposed that the rotary sleeve is formed by thecircumferential wall of a pot whose base has a mining knob. With respectto the rotary mounting of the metering drum, and as regards obtainingquantities of medicament for inhalation which are always the same, itproves advantageous if the rotary sleeve enclosed by an outer wall isunderpinned over a partial angular range by an inner wall section, whichforms the base of the portioning chamber formed in each case by one ofthe apertures. In this connection, it is also advantageous that thetransverse walls of the apertures extend in a trapezoidal shape or wedgeshape towards the center of the metering drum. This leads, as regardsthe transverse walls, to a convexly curved, trapezoidal trough ascompartment chamber, directed to the apex of a V, in other wordsdirected upwards. A further improvement, which is especially favourablefrom the point of view of production technology, lies in the fact thatall the air channels are incorporated in a support structure which canbe enclosed by two housing shells and in which the metering drum is alsomounted, and the housing shells form the cover for the air channels. Itcan also be provided for the support structure to form a stand for thedevice when designed as a standing appliance, the shoulder forming anengagement limit stop for the protective cap.

The following additional advantages are achieved by the invention:

The applicator is also suitable for medicament formulations which havepoor flow properties or which tend to cake. As a result of thesimultaneous homogenization upon each metering operation, any powderbridges which may be present are broken up and loosened.

It has also been found that the metering accuracy is not appreciablyimpaired in the event of slight deviations from the prescribed useposition; i.e. slight deviations from the use position are not criticalwith regard to the metering accuracy. After the metering, i.e. afteractuation of the metering drum, the inhalation can take place in anydesired position.

On account of the construction being amenable to injection-moulding, andon account of the small number of components required, the applicatorcan be manufactured cost-effectively and economically in large piecenumbers.

The subject matter of the invention is explained in greater detailhereinafter with reference to an exemplary embodiment which isillustrated in the drawing, in which:

FIG. 1 shows a plan view of the nasal applicator,

FIG. 2 shows a side view,

FIG. 3 shows a detail of the metering device in cross section,

FIG. 4 shows a plan view of a modified embodiment of the nasalapplicator.

The pocket-size device, hereinafter called the applicator, has, inaccordance with FIGS. 1 and 2, a long rectangular, pocket-size, flathousing 1. Its head area includes a so-called nasal applicator 2. In thedescription below, it is assumed that the applicator is located in avertical plane which corresponds to the plane of projection in thefigures.

The applicator includes a storage container 3 which is filled withpowdery medicare cut 4 (formulation).

The storage container 3 is formed by the interior of a metering drum 5.The metering drum 5 is mounted rotatably in the housing 1 and can beactuated directly from the outside by hand. It is located in the footarea of the applicator and in terms of volume uses up almost the entirewidth of the housing 1.

When it is being used, the applicator is held in such a way that themetering part is at the bottom and the adapter piece 2 with theapplicator opening 6 is at the top (use position). This position alsocorresponds to the representation chosen in FIG. 1 and FIG. 2.

When the applicator is in the use position, the metering drum 5 andadapter piece 2 thus in practice lie vertically one above the other. Thepowder particles are thus conveyed from the bottom upwards duringapplication.

The basic function of the metering drum 5 consists in that, during ametering operation, a defined quantity of medicament is brought from thestorage container 3 into a metering channel 7, by rotating the drum, andis conveyed from there, by means of a pulsed flow of air, through theapplicator opening 6 and into the nose. For this purpose, the meteringchannel 7 is connected on the one hand to an inflow channel 8 and on theother hand to an outflow channel 9 which leads to the applicator opening6 in the nasal adapter piece 2. The inflow channel 8 is connected via anoutlet valve 10 to a concertina bellows 11. Also arranged on theconcertina bellows 11 is an inlet valve 12. By actuating the concertinabellows 11 (compression), an air jet is generated which flows via theinflow channel 8 into the metering channel 7 and there expels thequantity of medicament, which has been made ready, through the adjoiningoutflow channel 9 and through the applicator opening 6 into thepatient's nose. Thus, in the metering channel 7, the precisely meteredquantity of powder which has been removed from the storage container 3is exposed to the compressed air jet and expelled.

For this purpose, the metering drum 5 has portioning chambers 13 whichare open on the channel side. As a result of the circular curvature ofthe metering drum 5, the portioned-off medicament (formulation) is madeready in the metering channel 7 as a forwardly bulging layer. Theresulting dome of medicament can be cleared off and out withparticularly favourable flow characteristics. The convex curvature ofthe domes of medicament can be seen particularly clearly from FIG. 3.There, the additional height y (seen in the chord center) resulting fromthe curvature of the portioning chamber 13 is easily discernible fromthe radials R directed at the center of the metering drum 5. The centerlies on the geometric axis of rotation of the metering drum 5.

As can be seen from FIG. 1, and in particular from FIG. 3, a portioningchamber 13 is formed by an aperture 14 in a rotary sleeve 15 of thepot-shaped metering drum 5. According to FIG. 1, four apertures 14 orportioning chambers 13 are distributed uniformly around thecircumference of the rotary sleeve 15. The apertures 14 are delimited byside walls 16 which are bevelled in such a way that the apertures 14taper towards the center of the metering drum 5. The bevel angle lies at45° to the shortest connection between the outer surface and innersurface of the metering drum wall. The transverse walls 16 give theportioning chamber 13 the shape of a trapezoidal, outwardly opening,curved trough which is of considerably greater length than width.

The rotary sleeve 15 is mounted rotatably between an annular wall 17 anda likewise annular wall section 18 which extends over an arc angle ofapproximately 180°. The approximately semicircular, web-shaped wallsection 18 is here arranged in such a way that it on the one hand formsthe base area of the metering channel 7 and at no point is there acontinuous connection between the air channels 8 and 9 and the storagecontainer 3, and, on the other hand, at the lower end leaves the footzone of the rotary sleeve 15 free (see FIG. 1). The annular wall 17 andthe wall section 18 are formed integrally on the housing 1. The mountingof the rotary sleeve can be improved by means of a beating collar whichis approximately 1 to 2 mm high and which extends, as a continuation ofthe said wall section 18, over the remaining circumferential angle andis similarly formed integrally on the housing 1. In this way, thecircumferential surface of the rotary sleeve 15 is guided with precisionrotation in the annular gap between the annular wall 17 and the wallsection 18 including the said bearing collar. The annular wall 17 has aninlet window 19 facing the metering channel 7. The side surfaces 19a ofthe inlet window 19 are bevelled in such a way that they are flush withthe side surfaces 16 of the portioning chamber 13 when the portioningchamber 13 is located exactly under the inlet window 19. As long as aportioning chamber 13 is located within the angle range of the wallsection 18, the outer surface of the wall section 18 functions as a basefor the trough-shaped portioning chamber 13. For this reason, the heightof the web-shaped wall section 18 is dimensioned slightly greater thanthe width of the aperture 14. Upon a further rotation of the rotarysleeve 15 in the clockwise direction, i.e. after the portioning chamber13 under the inlet window 19 has advanced beyond the tight, upper end ofthe wall section 18, the base of the portioning chamber 13 is open, sothat it once again communicates with the storage container 3.

The said wall section 18 in the area of the metering channel 7 functionswith its outer surface as base, whereas in the region of the ascendingportioning chamber, leading in the clockwise direction, it shields fromthe storage container on the inside the quantity of powder, taken fromthe powder reservoir, of the next aperture 14. In FIG. 1 this portioningchamber is located at an "8 o'clock position", while the portioningchamber ready for inhalation is at an "11 o'clock position". The loadingof a portioning chamber 13 is effected by means of the associatedaperture 14 being pushed forwards under the powder reservoir 4 uponfurther rotation of the rotary sleeve 15 (in FIG. 1 roughly in a zone offrom "4 o'clock" to "6 o'clock"), whereupon this portioning chamber 13fills with the powder. Upon further rotation of the rotary sleeve 15,this portioning chamber passes into the ascending region between "6o'clock" and "9 o'clock". In this region, the inhalation dose is securedin the portioning chamber by the shielding effect of the wall section18, whose lower end functions as a stripper, so that any excess powderdirected inwards is scraped off. An exact dose with reproducible powderdensity is achieved in this way.

The wall section 18 leaves about 180° open to the interior of thestorage container 3. The rotary sleeve 15 acts as a rotary slide. If themetered quantity of powder is not removed, it passes automatically backinto the reservoir, in other words the storage container 3, upon furtherrotation of the metering drum 15. Quantity accumulation is not possible.This important advantage derives from the vertical orientation of thefunctional elements.

The circumferential wall of the rotary sleeve 15 of the pot-shapedmetering drum 5 is provided on the outside with a convenientlyaccessible turning knob 20 (see FIG. 2 in particular).

A plurality of loosening fingers 21 are arranged on the base of the pot,parallel to the axis of rotation of the metering drum 5 and distributeduniformly about the circumference, the said loosening fingers 21projecting into the powder reservoir and their radial spacing from thecenter being chosen such that they scrape across the rear of the wallsection 18 during rotation, so that no powder can settle there. Viewedin the clockwise direction, in accordance with FIG. 1, one looseningfinger 21 is arranged immediately behind each aperture 14 (leading).Alternatively, or else in addition, the loosening fingers can bearranged stationary on the housing 1, in which case the drum movement issimilarly used for loosening the powder.

The applicator housing 1 consists of two housing shells 22 and 23 whichare U-shaped in cross-section. The two shells 22 and 23 enclose, insandwich fashion, a support structure (not shown) as core part, in whichthere are accommodated, as essential components, the inflow channel 8,the metering channel 7 and the outflow channel 9, as well as a circularrecess for mounting the metering drum 5. The air channels 7, 8, 9 areprovided for in the form of groove-like depressions of approximatelyrectangular cross-section and are closed off or covered by the housingshells 22 and 23. This construction guarantees a sufficient mechanicalstability, even when the support structure is designed with a relativelythin wall (e.g. about 5 mm) for reasons of reducing weight.

The housing parts 22, 23 can be fastened using a damping technique; anadhesive bonding or thermal bonding is likewise conceivable, unless thecomplete or partial dismantling of the housing 1 is sought for cleaningpurposes or refilling purposes. In this case, the usual traditionalmeans of fastening, such as screw connections, etc., are then to bepreferred.

In the modified embodiment of the applicator according to FIG. 4, thecompressed air source consists of a manually actuated reciprocating pump24 which has a pump piston 26 displaceable in a pump chamber 25 and witha hand grip 27 and a valve 28. The pump chamber 25 is connected here tothe inflow chamber 8 via a compression chamber 29. At the entrance tothe compression chamber 29 (as viewed from the pump chamber) there is aninlet valve 30. By actuating a release button 31 which is pretensionedby means of a spring, the compression chamber 29 can be connected to theinflow channel 8.

The function of the applicators according to FIGS. 1 to 4 will bedescribed again hereinbelow.

According to FIG. 1, the powdery medicament is located inside the rotarysleeve 15 and there reaches into the lower portioning chambers 13. Whenthe rotary sleeve 15 is turned, the filled portioning chamber 13 thenfirst comes between the annular wall 17 and the wall section 18. Theportioning chamber 13 can empty only when it is rotated into the regionof the metering channel 7, since here the annular wall 17 isinterrupted. The user introduces the device via the nasal adapter piece2 into the nose. By compressing the concertina bellows 11, a volume ofair is forced into the metering channel 7 via the pressure valve 10. Theportioning chamber 13 standing by is emptied by means of the resultingair jet, and the contents of the chamber are blown into the nose withthe flow of air. When the concertina bellows 11 is then released, thepressure valve 10 (outlet valve) closes, while at the same time theinlet valve 12 opens in order to allow air to flow into the concertinabellows 11.

According to FIG. 4, the powdery medicament is again made ready in therotary sleeve 15, the portioning chambers 13 lying at the bottom fillingwith the powder. When the rotary sleeve 15 is turned, the powderymedicament is in this case loosened by loosening pins 21 arranged in thesleeve, so as to obtain a good flow. By pushing the pump piston 26 upvia the hand grip 27, the air contained in the pump chamber 25 isdisplaced into the compression chamber 29 via the pressure valve 28 andthe inlet valve 30. If a portioning chamber 13 filled with themedicament has been brought beforehand into a standby position in themetering channel 7 by means of actuating the metering drum 5, then theair compressed in the compression chamber is released by means ofpressing the release button 31, so that a pulsed flow of air (air jet)flows through the downstream inflow channel 8 at high speed, completelyentrains the quantity of powdery medicament standing by in the meteringchannel and transports it through the outflow channel 9 and theapplicator opening 6 into the patient's nose.

We claim:
 1. A powdered medication inhaler comprising a manuallyactuated air source, an inflow channel (8) having two ends, an outflowchannel (9) having two ends and a metering channel (7) having two ends,said manually actuated air source being connected to one end of saidinflow channel (8), one end of said metering channel (7) being connectedto the other end of said inflow channel (8) and the other end ofmetering channel (7) being connected to one end of said outflow channel(9), the other end of outflow channel (9) comprising an opening fordischarging powder out of the inhaler; a metering drum (5), the interiorof which comprises a powder storage container (3) and having portioningchambers (13) for metering predetermined quantities of powder from saidpowder storage container (3) to said metering channel (7) whereby, inoperation, the rotation of metering drum (5) causes portioning chamber(13) to remove a predetermined quantity of powder from powder storagecontainer (3) and place it in metering channel (7), and air introducedinto inflow channel (8) by said manually actuated air source flows frominflow channel (8) into metering channel (7), entrains saidpredetermined quantity of powder placed in metering channel (7) by saidportioning chamber (13), and carries it through outflow channel (9) andout of the inhaler.
 2. An inhaler according to claim 1, wherein themetering drum (5) further comprises a rotary sleeve (15) on thecircumference of which the portioning chambers (13) are arranged.
 3. Aninhaler according to claim 2, wherein the rotary sleeve (15) is formedby the circumferential wall of a pot, on the base of which a turningknob (20) is arranged.
 4. An inhaler according to claim 2, wherein therotary sleeve (15) is enclosed by an annular wall (17) and isunderpinned, over a partial angle range, by an inner wall section (18)which forms the base of the portioning chamber (13) formed in each caseby an aperture (14).
 5. An inhaler according to claim 4, whereinapertures (14) have transverse walls (16) which extend in trapezoidalshape and wedge shape in the direction of the center of the meteringdrum (5).
 6. An inhaler according to claim 2, wherein the channels (7,8, 9) are accommodated in a support structure which can be enclosed bytwo housing shells (22, 23) and in which the metering drum (5) is alsomounted, the housing shells (22, 23) forming the cover for the channels(7, 8, 9).
 7. An inhaler according to claim 1, wherein the air sourceconsists of a concertina bellows (11).
 8. An inhaler according to claim1, wherein said air source is a compressed air source and a compressionchamber (29) is arranged between the compressed air source and inflowchannel (8), and a release button (31) is arranged between thecompression chamber (29) and the inflow channel (8), the air supplystored in the compression chamber (29) being released upon actuation ofthe release button (31).